A long-running debate over the merits of eating less salt escalated Wednesday when one of the most comprehensive studies yet suggested cutting back on sodium too much actually poses health hazards.

Current guidelines from U.S. government agencies, the World Health Organization, the American Heart Association and other groups set daily dietary sodium targets between 1,500 and 2,300 milligrams or lower, well below the average U.S. daily consumption of about 3,400 milligrams.

The new study, which tracked more than 100,000 people from 17 countries over an average of more than three years, found that those who consumed fewer than 3,000 milligrams of sodium a day had a 27% higher risk of death or a serious event such as a heart attack or stroke in that period than those whose intake was estimated at 3,000 to 6,000 milligrams. Risk of death or other major events increased with intake above 6,000 milligrams.

The findings, published in the New England Journal of Medicine, are the latest to challenge the benefit of aggressively low sodium targets—especially for generally healthy people. Last year, a report from the Institute of Medicine, which advises Congress on health issues, didn't find evidence that cutting sodium intake below 2,300 milligrams reduced risk of cardiovascular disease.

The new report has shortcomings, and as an observational study it found only an association, not a causative effect, between very low sodium and cardiovascular risk. Still, it spurred calls to reconsider the targets.

These studies drive dietitians nuts. You will be happy to know that RDs loudly and frequently voiced opposition to the guidelines setting sodium levels at 1500 mg - 2300 mg daily. Unrealistic and unsafe. We are delighted to see any studies supportive of realistic and safe levels, and hope for more.